Toxic coating composition and method of applying said composition to wood



United States Patent TOXIC COATING COMPOSITION AND METHOD OF APPLYINGSAID COMPOSITION TO WOOD Wayne K. Davis, Oakland, Calif.

No Drawing. Application September 4, 1951, Serial No. 245,085

4 Claims. (Cl. 117-149) .My invention relates to the protection of woodand wood structures against wood-destroying organisms such as termitesand fungus, and more particularly to material .and method of protectingwood and wood structures against such infestation.

Many methods have been attempted or devised to employ chemicals havinginsecticidal or fungicidal qualities, in the treatment of wood, byapplying them to Wood or wood structures at various stages ofmanufacture or use. Pressure treating in retorts, dipping, spraying andpainting are the most common methods of application. Of theaforementioned methods, the first two, namely that of pressure treatingin retorts and dipping, can satisfactorily be employed only where thewood or wood structure is not to be altered subsequent to suchtreatment. However, when such wood or lumber is to be nailed, sawed orotherwise mutilated, as is the case when such wood is to be employed inthe fabrication of a structure such as a home, the untreated interiorportions of the wood then become exposed, and the protective effect ofthe treatment is to a substantial degree, nullified. Also, thesubsequent effect of seasoning, serves to open cracks into the untreatedinterior portions of the wood, thus providing access to wood-destroyingorganisms.

As for the procedure of treating wood by painting or spraying, suchtreatment is much less effective than pres sure treating in retorts ordipping, unless the procedure of painting or spraying is repeated manytimes.

Among the objects of the present invention are:

(1) To provide a novel and improved method for treatment of Wood andparticularly structural members of a completed structure;

(2) To provide a novel and improved method of treating wood structuralmembers, which will completely cover unexposed surfaces within joints,seams, nail holes, etc.;

(3) To provide a novel and improved method of treating wood structuralmembers, which is simple but extremely eificient;

(4) To provide a novel and improved method of treating wood, which willproduce deep penetration of protective material into the wood;

(5) To provide a novel and improved method of treating wood structuralmembers, which method requires but a single visit on the part of theworkman;

(6) To provide a novel and improved method for the teratment ofstructural members of wood, which method can be performed by unskilledlabor;

(7) To provide a novel and improved material for treatment of wood;

(8) To provide a novel and improved material for treatment of wood, suchmaterial being in heavy paste form suflicient to be self sustaining andresist flow, when applied in layer thicknesses of an inch or so tovertical surfaces;

(9) To provide a novel and improved material for teratment of wood,which will penetrate deeply and displace moisture from wood in theprocess of penetration;

2,708,640 Patented May 17 1955 (10) To provide a novel and improvedmaterial for teratment of wood which will, of its own accord, penetratejoints, crevices, cracks, nail holes, etc., and impregnate the unexposedsurfaces thereof;

(11) To provide a novel and improved material for treatment of Woodwhich when applied to a wood surface will reelase toxic material for anextended period of time;

(12) To provide a novel and improved material in paste form fortreatment of wood, which material will extend its protective effect toan area substantially greater than the area of application;

(13) To provide a novel and improved material for treatment of wood,which eliminates the need for containers, wicks, or the like.

Additional objects of my invention will be brought out in the followingdescription of the same.

The method of the present invention involves the preparation of a thickadhesive paste material incorporating therein, in releasable form,chemicalswhich' fu'nction'as fungicides and insecticides. Preferably,the material 'involved, is in the form of an emulsion of theoil-in-water type, in which the fungicidal and insecticidal chemicalsare primarily carriedin solution in the oil phase. The emulsion isprepared to a sufficiently thick pasty consistency, as to beself-sustaining, even when applied to a vertical surface in a layer ofthe order of one-half to one inch thick.

One example of a formula for the preparation of an emulsion of thischaracter is as follows:

Water, 2 /2 gallons Triethanolamine, 3 pints The water andtriethanolamine are mixed to constitute the water phase, and followingagitation thereof to ob tain a thorough mixture, the remainingingredients constituting the oil phase, are gradually added withcontinued agitation until the desired consistency is attained.

A similarly usable emulsion may be prepared by mixing 2% gallons ofwater and 45 cubic centimeters of ammonium hydroxide with casein in theamount of 8 ounces, to constitute the water phase, and while agitatingthe same, adding 5% solution of pentachlorophenol in stove oil to theextent of approximately 27 gallons, to obtain the desired consistency.

In each of the foregoing preparations, the principal chemical involvedis pentachlorophenol, which is effective both as a fungicide and as aninsecticide. However, other toxic materials can be added or substitutedin the preparation of the emulsion, to provide a wider range ofeifectiveness. Likewise, the proportions of the ingredients are notcritical, but may be varied to obtain special results.

In utilizing the foregoing material for its intended purpose, theemulsion is applied as a heavy covering up to an inch or so inthickness, to the wood to be protected, and in a general way, to thearea to be treated. The oil phase in the emulsion has the faculty ofspreading and gradually penetrating the wood structure to a substantialdepth over a period of time, during which, a film forms over thematerial which inhibits rapid evaporation of the material into theatmosphere and minimizes attendant odor. The gradual breakdown of theemulsion affords the material considerable time, of the order of two orthree weeks, in which to become absorbed into the wood structure.

The toxic ingredient being dissolved principally in the oil phase of theemulsion, will thereby be carried over an extended surface area and deepinto the wood structure. By reason of such characteristics of thematerial involved, the material will penetrate the adjacent joints,cracks, nail holes and the like, which would otherwise be inaccessible,and impregnate the unexposed surfaces thereof with the toxicingredients. Inasmuch as termites, for example, seek such secludedplaces for their activities, the self-spreading and penetratingcharacteristics of the material constitute an important factor of thepresent invention.

It will be apparent, also, in the practice of the above describedmethod, that no special tools or equipment are necessary, in that thematerial may be smeared on with a spatula or any conveniently handy thinflat piece of wood. Thus no containers or wicks need be employed, andthis eliminates the necessity of a return trip on the part of a workmanto retrieve such items which in the aggregate would represent aninvestment that could not be ignored.

It will be apparent that the invention as described above, fulfills allthe objects attributable thereto, and

while I have described the same in its preferred form, the

invention is subject to some alteration or modification withoutdeparting from the underlying principles involved therein, and Iaccordingly do not desire to be limited in my protection to such detailsas I have described, except as may be necessitated by the appendedclaims.

I claim:

l. The method of treating wood structure as a protection againsttermites, fungus and the like, which comprises applying to at least aportion of the porous surfaces of the wood, a semi-stable, highlyviscous, self-sustaining oil-in-water emulsion, consisting essentiallyof an oil soluble fungicide and insecticide, a major amount of oil, aminor amount of water, and an emulsifying agent, in a coating of theorder of one-half inch thickness, whereby the emulsion will slowly breakdown and the fungicide l and insecticide in oil solution will beabsorbed in the wood over a period of days.

2. The method of treating wood structure as a protection againsttermites, fungus and the like, which comprises applying to at least aportion of the porous surfaces the order of one-half inch thickness andallowed to break down over a period of days whereby the oil and oilsoluble constituents are absorbed by the wood, the emulsion consistingessentially of hydrocarbon oil, present in major quantity, oil solublefungicide and insecticide, water, and emulsifier, said emulsion being ofthe oil-in-water type and highly viscous, non free-flowing andself-sustaining.

4. An emulsion ready for use in treating porous wood surface wherein aviscous non-flowing self-sustaining emulsion is applied to the surfaceof the wood in a coating of the order of one-half inch thickness, andallowed to break down over a period of days whereby the oil and oilsoluble constituents are absorbed by the wood,

the emulsion consisting essentially of hydrocarbon oil, present in majorquantity, pentachlorophenol, water, and emulsifier, said emulsion beingof the oil-in-water type and highly viscous, non free-flowing andself-sustaining.

UNITED STATES PATENTS 1,565,503 Henderson Dec. 15, 1925 1,809,016Brogden June 9, 1931 2,012,975 Schmittutz Sept. 3, 1935 2,034,152Parrish Mar. 17, 1936 2,182,081 Hatfield Dec. 5 ,1939 2,206,520 TisdaleJuly 2, 1940 2,209,970 Hay Aug. 6, 1940 2,296,401 Perkins Sept. 22, 19422,447,475 Kaberg Aug. 17, 1948

1. THE METHOD OF TREATING WOOL STRUCTURE AS A PROTECTION AGAINSTTERMITES, FUNGUS AND THE LIKE, WHICH COMPRISES APPLYING TO AT LEAST APORTION OF THE POROUS SURFACES OF THE WOOD, A SEMI-STABLE, HIGHLYVISCOUS, SELF-SUSTAINING OIL-IN-WATER EMUSLION, CONSISTING ESSENTIALLYOF AN OIL SOLUBLE FUNGICIDE AND INSECTICIDE, A MAJOR AMOUNT OF OIL, AMINOR AMOUNT OF WATER, AND AN EMULSIFYING AGENT, IN A COATING OF THEORDER OF ONE-HALF INCH THICKNESS, WHEREBY THE EMULSION WILL SLOWLY BREAKDOWN AND THE FUNGICIDE AND INSECTICIDE IN OIL SOLUTION WILL BE ABSORBEDIN THE WOOD OVER A PERIOD OF DAYS.